Forensic Science
Questioned Documents
Documentation
Questioned Documents
 Involves the examination of handwriting, ink, paper, etc. to
ascertain the source or authenticity
 Examples include letters, checks, licenses, contracts, wills,
passports, etc.
 Topics





Handwriting analysis
Ink (and pens)
Paper (and pencils)
Forgery
Codes and Ciphers
Comparison
Graphologist - attempts to predict character traits
from handwriting examination
Forensic Document Examiner - involves the analysis
and comparison of questioned documents with
known material in order to identify whenever
possible, the author or origin of the questioned
document.
Unfortunately, no federal licensing exists. There is
certification through the ABFDE.
Handwriting
Handwriting analysis involves
two phases:
The hardware--ink, paper,
pens, pencils, typewriter,
printers
Visual examination
Handwriting Identification
“ACE”
• Analysis of the “knowns” with a determination of the
characteristics found in the known
• Analysis of the questioned or unknown writing and
determination of its characteristics
• Comparison of the questioned writing with the known
writing.
• Evaluation of the evidence, including the similarities and
dissimilarities between the “questioned” and “known”
writing.
Handwriting Analysis
Handwriting sample of
President George Bush
According to Sheila Lowe in
her book, Handwriting of the
Famous and Infamous,
President Bush’s handwriting is
“fast and highly simplified in
fairly well-organized writing
field”.
Is this a forensic document
examiner or a graphologist??
Handwriting Samples
• The subject should not be shown the questioned
document
• The subject is not told how to spell words or use
punctuation
• The subject should use materials similar to those of the
document
• The dictated text should match some parts of the
document
• The subject should be asked to sign the text
• Always have a witness
Linguist
Experts that look at the linguistic content
(the way something is written) of a
questioned document.
Language that is used can help to establish
the writer’s age, gender, ethnicity, level of
education, professional training, and
ideology.
Exemplar – Handwriting sample
that is the known sample….
the standard
Does asking for your handwriting
violate your rights?
Answer: Nope
5th Amendment – (the right not to
incriminate yourself or testify against
yourself)…. The U.S. Supreme Court decided
that handwriting is a part of identifying
physical characteristics that aren’t protected
against ‘the 5th’
And what about that 4th?
The U.S. Supreme Court decided that providing
a handwriting sample doesn’t violate the 4th
Amendment’s protections against unreasonable
search and seizure.
Let’s talk about Forgery
Forgery – writing or altering a document
with intent to defraud
Role of forensic examiner: Was the
document altered?
Role of judge/jury: Was it the writer’s intent
to defraud?
2 Common Ways to Forge
1. Freehand
Simulation
2. Tracing
Common Clues That Give Away
Forgery
•
•
•
•
•
•
•
Underlying tracing
Forger’s tremors (shakiness in the writing)
Uneven writing speed and pen pressure
Hesitations
Unusual pen lifts
Patching and retouching
Blunt beginnings and endings
Disguised Handwriting
A deception in which the writer attempts
to camouflage his/her handwriting
More Forgery Stuff
• Erasures – using an eraser… ultraviolet light,
microscope, lycopodium powder
• Obliterations – destroy document or obliterate the
writing…. Even burned paper can be sprayed,
treated with chemicals, even photographed
• Alterations – overwriting… like what you guys do
on your progress/grade reports… UV light shows 2
different pens easily
Indented Handwriting
Created when you write on the top page
and it indents the page underneath.
So, what would you do to reveal the
indented writing?
I knew you would say that.
FYI……
Putting pencil over the indented writing
tends to destroy the writing.
Use angled light, then photograph….. or
ESDA – electrostatic detection apparatus
Ink
Chromatography – process which
physically separate mixtures of
gases, liquids or dissolved
pigments.
Types
• Gas Chromatography
• HPLC - high-performance liquid
chromatography
• TLC - thin-layer chromatography
• Paper Chromatography
Paper Chromatography
with Ink
Two samples of black ink
from two different
manufacturers run using
paper chromatography.
Retention Factor (Rf)
• This is a number that
represents how far a
compound travels in a
particular solvent
• It is determined by
measuring the distance the
compound traveled and
dividing it by the distance
the solvent traveled.
Science Stuff
Gas chromatograph - separates mixtures on the
basis of their distribution between a stationary
liquid phase and a moving gas phase. The written
record of the results is called a chromatogram. A
typical one will show a series of peaks, with each
representing one component of the mixture. The
time required to go from the injection out of the
column is known as the retention. This allows
identification of class characteristics.
Gas Chromatography
More Science Stuff
Mass spectrometer - an instrument that connects to the
gas chromatograph. The substance to be identified is exposed to a beam of
high-energy electrons causing the molecules of the sample to lose electrons and
to acquire a positive charge. These positively charged molecules decompose into
numerous fragments. These fragments then pass through an electronic or
magnetic field where they are separated according to their masses. The unique
feature of mass spectrometry is that no two substances produce the same
fragmentation pattern, thus producing individual characteristics.
In other words… materials are separated into
individual components based on mass of
molecules.
Paper
•
•
•
•
Weight
Color
Water marks
Age
Pencils
• Lead
• Hardness Scale - a traditional measure
of the hardness of the "leads" (actually made
of graphite) in pencils. The hardness scale,
from softer to harder, takes the form ..., 3B,
2B, B, HB, F, H, 2H, 3H, 4H, ..., with the
standard "number 2" pencil being of
hardness 2H.
Codes and Ciphers
• Codes - letter combinations,
numbers or symbols used to
represent words or
concepts…Morse Code
– Interception from terrorists and other
war enemies
• Ciphers--a message in which letters
or symbols replace the actual
letters in the message.
CRAZY CRIMINALS
According to Point of View, a magazine published by
the Alameda county District Attorney’s office, a
guy walked into an Oakland bank and handed the
teller a note reading, “this is a stikkup. Hand over
all yer money fast.”
Guessing from this that the guy was no rocket scientist,
the teller replied, “I’ll hand over the cash as long as
you sign for it. It’s a bank policy that all robbers
have to sign for their money.”
The guy thought this over, then said “Uh, I guess that’s
OK.” He signed his full name and address. That’s
where the cops found him a few hours later.